Experimental study of the influence of bubble interaction on their characteristics during unsteady boiling in a flow of subcooled liquid
P.V. Khan1,2, A.A. Levin1,2
1Novosibirsk State University, Novosibirsk, Russia
2Melentiev Energy Systems Institute SB RAS, Irkutsk, Russia
Keywords: nucleate boiling in a flow of subcooled liquid, unsteady heat release, clusters of bubbles, pulsating bubbles
Abstract
The paper presents the experimental results on unsteady nucleate boiling on the heater surface with rapidly increasing surface temperature. Analysis of the results of high-speed video recording with a frequency of 180,000 frames per second and a spatial resolution of 5.5 μm per pixel shows that the input data for existing models of heat transfer during nucleate boiling must be refined to take into account the existence of cluster and pulsating bubbles. It has been established that bubbles, interacting through the exchange of momentum, heat and steam mass, accelerate the activation of neighboring vaporization sites, so the clusters of bubbles can form at the initial stage of covering the heater surface with steam. The main characteristics of isolated, cluster and pulsating bubbles have been studied for the wall overheating from 0 to 14 K above the temperature of nucleation onset and flow underheating from 23 to 103 K.
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